Party-line telephone system.



No. 842.772. PATENTED JAN. 29, 1907.

W. W; DEAN.

PARTY' LINEYTBLEPHONE SYSTEM. APPLICATION FILED APR.17,1905.

3 SHBETS -SHEE'IL1.

No. 842,772. PATENTED-JAN. 29, 1907.

W. W. DEAN. PARTY LINE TELEPHONE SYSTEM.

APPLI'GATION IILED,APB.17.1905.

3 SHEETS-SECRET 2.

.No. 842,772. PATENTED JAN. 29, 1907,;

' w. w. DEAN.

PARTY LINE TELEPHONE SYSTEM.

APPLICATION .IILED APR. 17; 1905.

3 SHEETS-SHEET 3,

- UNITED. STAMENTOFFICE. v

WILLIAM w. DEAN, or ELYRIA, or-no, ASSIGNOR TO THE DEAN ELECTRIC COlvIP-ANY, OFELYRLA, orno, A CORPORATION, or omo;

PARTY-LINE "TELEPHONE SYSTEM. Q J a Application filed April 17. 1905. Serial No. 255,961.

T001] whom it Titay canoern:

Be it. known that 1, WILLIAM W. DEAN, a citizen of the United States, residing at Elyria, in thecounty of Lorain and State of Ohio, have invented certain new and useful Improvements in Party-Line Telephone Syswhich the following is a. specifica-.

terns, tion, eference being had therein to the accompanying drawings.

My invention-relates to improvements in party-line telephone systems, and has for its object, generally speaking, an improved harmonic system for selective signaling and embodies the apparatus necessary in sucha system, which is shown in the most convenient form for the practical-open ation thereof In harmonic selective signaling systems i heretofore designed two methods have been employed. By one a reed tuned to exact pitch was relied upon to close a circuit, and y the other a mechanical signal included directly in the harmonic circuit was overtuned or undertuned to allow for losses or acceleration in operation. A thirdmethodthat of exact tuning of the mechanical elementshas been attem ted at divers times, but has ingcurrent to positively never succeeds ,to my knowledge, prior to my present invention. The first and second methods need not be considered here, my present invention relating particularly to the third method. Systems of this type have heretofore been unsuccessful and uncommer= cialfor several reasons. It was found diflicult, if not impossible, to operate a bell having-a tongue constitutinga tuned reed by means of the ordinary pulsatingor alternating current of a frequencyor. pitch corresponding to 7 that of the bell-reed. The weight of the hammer or clapper, the manner of applying the attractive force ,of the magnet, and the reactive effect of the vibrating gong have always proved a source of trouble in attempting to reach a perfect tune. I have discovered, however, that it is possible by properly'applying the energy .of the ringovercome and render negligible the disturbing forces to which I have referred. In other words, without unduly increasing either the voltage or the ampere-turns in the ringer magnets-I apply the energy cumulatively in such manner as to reach an effective totality of suflicient turhing elements negligible.

' Specification of Letters Patent.

the provision of Patented Jan. 29. 1907.

Expressed in a few words, my invention comprises a polarized'ringer having its armature mounted in a neutral-position upon a strong springso strong that ordinary ring- I ing-current. momentarily applied produces no effect. Only when current of the proper frequency has'passed through the ringercoils for a long enough eriod to start up the armature and the tuned clapper do the gon s receive any stroke. I tune the clapper-rods or reeds by fastening thereon clappers formed in cylindrical'shape and of different lengths and weights. v

My invention is illustrated in the accompanying drawings,'in which Figure. 1 is a front view of a ringer with gongs mounted'complete. Fig. 2 is an end view of the same. Fig. 3 is atop planview with the gongs removed. Fig. 4 is-a bottom plan view. Fi 5 is a perspective view of the clapper-r0 and connected parts removed, and Fig. 6 is a diagram of a subscribers line having four stations equipped with my invention and the cooperating central-office apparatus. I

I will first describe the mechanical structure of my ringer and then point out the method of its employment. I

Referring to Figs. 1 to 5,'A designates. a pair of magnet-spools, with cores (1 a, secured by screws (1 upon the yoke B. Atthe lower ends of these cores is carried a secondary nonemagnetic yoke B the same being secured by the nuts b 6 upon the sleeves 12 secured. to the magnet-heads or in any other suitable manner. The yoke B has front and rear drop portions 6 I), each slotted, as indicated at b for the reception of the ends '0 c of the armature these is fitted a lock-nutgc its connected arts are best shown in Figs. 4 i and 5. The Block C is preferably squared throughout that port-ion of its length which lies between the parts 6 6 its ends being re duced and threaded at c c'.- The squared portion is Irilled out on one side to receive the stiff short leaf-s ring 0 To hold this in position on the b ock, a short bar 0 is clamed upon it by means of screws c Secure uponthe springabove the block is the armature C. his is made of pressed nzetal in two halves 0 each having an upstanding flange "c or c. These'two flanges are set upon opposlte sldesof the spring andsecured.

This block and together through the latter by means ofrivblock or bolt 0; On each of ets c. Each flange is formed with a semicylindrical channe to one side of the spring and an outside rivet 0 the channels when put together receiving the cla perrod G which is thus secured rigidly to te armature structure by the common binding means. At its upper end the clapper-rod is fitted with the clapiprer C, composed of a length of tubing solidly iven on the rod. The length of this tube varies according to the tune desired.

In assembling the device the ends of the block 0 .are inserted from beneath into the slots b the clapper-rod at the same time gassing up through an opening 0 in the oke and lying front of the upper yo e B between the gongs G. The armature having been adjusted with regard to the poles a of the ringer-magnet the nuts 0 are set up tightly, and thereafter the onl movement of the armature possible to ma e is that permitted by bending the spring C Secured upon the upper yoke and passing down behind the magnets into contact with the rear nut c is the 1permanent magnet M, and as the upper yoke and the block 0, with its parts, are of H011 it follows that a very efficient magnetic circuit is thus obtained, the only breaks in which are the air-gaps between the poles a and the armature C. The gongs G are mounted upon posts 9, the latter being carried upon metal segments 6 each pivoted at b upon a suitable bolt passing through the yoke B. At its front. edge 6 each segment is provided with gear-teeth meshing with the worm 6 out on the stem of the bolt 6. This bolt 6 has its ends supported inelro bearings formed in hook shape on the yo e B, as shown at b, Figs. 1, 2, and 3. In order to get the best results with this ringer,

'an accurate adjustment'of the gongs is 'nec' essar and this adjustment, moreover, must be so id,' so that when the parts are once set they will remain undisturbed by the forcible action which I contemplate. The gongposts .pass up from the segments through ateral enlarged openings bin extensions b on the yoke B. By means of a suitable wrench applied to the head of either bolt b the same may be turned, and the worm thereon will move the segment one way or the other andwith it the gong-post and gong.

It will be observed that the construction of my ringer throughout is such as to make it very solid'and substantial. Its depreciation through a long eriod of time is intended to be negligible an its 0 eration uniformly efficient throughout its 'fe. It is so designed that it may be substituted for an ordinary bridging ringer or, in fact, for any ringer at any station, having parts of standard type.- The sizes and general arrangement of parts are such that no special features are required in the rest of the telephone set to permit the use of this ringer.

Referring now to Fig. 6, I have shown a .due lto reactive vibration from the Thus I start my selective ringer by tuning it pair of plugs P P, connected by'a cord-circuit 3 4 5 6, and provided with a listening-.

' key Kandringing-keys K, K K andK.

A subscriber's line 1 2 terminates at contact nof the cut-off relay N, by which the line is adapted normalfiyl -Ito be connected -to a signalrelay L, contro g a lamp Z, and when a plug is in one of the jacks J or J, to be connected thereto and disconnected from the relay. The cord-circuit contains the four relays R, R, R and R bridged in pairs across the two ends of the circuit, each pair jointly controlling one of the supervisory lamps r 1". Current is furnished by central batteries Q. From one of these the wire 12 extends as a common return for the line-relays, and also connected through resistance rh by branch 11 as a common return for the selective ringing-keys, battery-current being thus supplied to the sleeve side of line forjthe cut-off relay N while Each of the selective keys K, K K an K, is-connected .on'one side by wire 7 8, 9,-or 10 toa generator giving a particular frequency, so that by using the proper key any one of four freuencies may be thrownu on the line. At the f our subscribers stations ,X, Y, and Z, the four ringers are all tuned to respond to different frequencies. At station W the tubular clapper C is long and heavy, this station be ing called by the lowest frequency current. At stations X and Y the length and weight of the clapper is successively reduced, and at station Z it is shortest and lowest of all, this station being called by the current of highest frequency. It is. to be understood that momentary current of right or wrong frequency will not effectively move any of the four armatures. If 'the current continues to flow for a brief period, however, the

armature at that station which is tuned to respond to the selected frequency gradually getsinto motion. As it is pulled over the strength of the magnetic pole strongly increases, and in order to get a powerful effect, and,in fact,relying as I do upon what might be termed sheer'brute force, I discard all delicate adjustments and safeguards and strip the magnet-pole, so that the armature may come into direct contact with it. I thus get a maximum pull and a maximum effecton the clapper. just when I need it the mostthat is, at the instant of possible interference or g.

exactly, so that it will respond before striking the gong and after it has once started to vibrating I provide a strong enough action to It will be noted that I have shown condensers in the bell branches at my substations. I employ .these condensers in some cases in conjunction with the windings of the magnets for the purpose of electrically tuning the branches. While my system is preferably operative without this, it is particue larly adapted for use in common battery systems, the small leakage through the branches not tuned to receive a particular ringing-current being negligible on account of the stiffness of the springs C Thus the ringer at the desired station only ,will get current enough to start its armature into vibration, irrespective of its mechanical tune, and, as I have stated in the foregoing, this initial vi- .bration is essential to full actuation, as the normal position of the armature is too far from the poles of the magnet for instantaneous pulls to be effected against the stiffness of the springs.

Although I have described the bells at the substation connected in series and have. described the system' in the most specific way so as to make it clear to the understanding, many modifications will be apparent to those "versed in the art, and all such modifications are contemplated and are considered to be within the scope and purview of the appended claims. 1

Having thus described my invention, what I claim, and desire to secure byLetters Patent, is.

1. A selectivepaity-line telephone system, comprising means at the central office for throwing selective ringing-currents of different predetermined frequencies upon a line; a

plurality of stations connected to said line, and a ringer at each station having its armature and clapper-rod normally held against movement in response to any but a strong force; and naked pole-pieces adapted to touch the armature at the end of each stroke,

whereby after initial vibration is set up a ringer in response to pro er current, its moving parts Wlll be expose to a strong and cumulative force sufficient toinsure full operation, substantially as described.

2. In a party-line telephone system, the combination with a telephonedine, of a. plurality of substations located 011 the line, a

bell at each substation provided with a constant to thereby permit the desired operation of the bells, substantially as described.

3. In a party-line telephone system, the combination with a telephone-line, of a-plurality of substations located on the line, a bell at each substation'provided with naked magnet-poles exposed to its armature and with a stiffened reed-tongue, the operative rate of actuation of the bells being the natural rate of vibration of the reed-tongues unmodified by the action of the gongs of the bells in being struck, a generating apparatus at the central office consisting "of an electric motor and a plurality of generators mounted upon a common shaft, agovernor to maintain the speedof said motor and generators constant, said generators being arranged to deliver ringing-current to the line of frequencies corresponding to such operative rates of actuation of the bells, substantially as described.

4:. In a party-line tele hone system, the

combination with a telep one-line, of a plurality of substations located on the line, bells provided with armatures ex osed to naked poles and with stiffened ree -tongues at the substations in branches of the line conductors, each reed having a characteristic rate of actuation, means at the central ofifice for impressing ringing-current upon the line of 9 5 frequencies corresponding to each characteristic rates of actuation of the reeds, and means including. the coils of the bells for electrically attuning said bell branches to the ringing-currents ofthe associated bells, substantially as described.

-5. In a party-line telephone system, the combination with a telephone-line, of a plurality of substations located on the line, bells provided with armatures exposed to naked poles and with stiffened tuned reed-tongues at thesubstations in branches of the line conductors, each reed having acharacter-' istic rate of actuation, and means at the central office for impressing ringing-current upon the line of frequencies corresponding to such characteristic rates of actuation of the reeds.

6. In a party-line tele hone system, the combination with a telep one-line, of a plurality of substations located on the line, bells provided with armatures exposed to naked poles and with stiffened tuned reed-tongues at the substation in branches of the line conductors, each reed having a characteristic rate of actuation, condensers in said branches, and means at the central office for impressing ringing-current upon the line of frequencies corresponding to such characteristic rates of actuation of the reeds.

In testimony whereof I affix my signature in presence of twowitnesses.

\VILLIAM W. DEAN:

Witnesses:

SIDNEY A. BEYLAND, A. D. T; LLBBY. 

